The ability to measure factors relating to the appearance of metal plated objects is important and necessary to those engaged in appearance science, because the unaided human eye, although sensitive and discriminating, cannot make the qualitative and quantitative judgments which are necessary and suitable for reproducible records.
With respect to the prior art, gold and silver plated buttons have been standardized and specified according to their size, quantity of metal plated, and their color. All of the above standards have quantitative values according to their specifications, except for the color. This parameter is compared and interpreted visually against samples kept for reference purposes by the manufacturer and the customer. This procedure results in inconsistent color matching and has often resulted in disputes among manufacturers and their customers, rejections and costly and time-consuming reworking of these articles.
One reason for inconsistent color determinations is a phenomenon known as metamerism which occurs when two colors which match under the illuminant do not match under another illuminant. Also, the high intensity of the specular reflection from metal plated objects prevents the eye from discriminating between small differences in surface texture, especially when such an object is embossed and/or ornamented.
Due to the above mentioned considerations, the objective of those in the art has been to perfect a means by which one may quantitatively measure the color of a manufactured metal plated object. The Hunter Lab Scales, devised in 1958, have been found to be the most suitable color meter, based upon Ewald Hering's opponent colors theory of vision. This theory holds that the sensations of red and green, yellow and blue, and white and black are paired on specified retinal cone structures in the eye. Each cone substance evokes one sensation when it is changed (decomposed) by light and the paired color is sensed when the cone reforms or is resynthesized to its original state.
Difficulties arise because instruments capable of quantitative measurements of brightness, geometric or chromatic attributes of appearance, such as color, gloss, opacity, haze, and whiteness or yellowness of articles, only work well with flat surfaces. Embossed or ornamented buttons are seldom fabricated flat, and are usually convex. Quantitative measurements by existing color instruments such as colorimeters cannot generate precise and reproducible results unless the buttons can be positioned in the instrument in a standardized, reproducible manner.
The applicant has discovered an apparatus and method which will enhance the measuring capabilities of color measuring devices. The invention is capable of positioning non-standard, embossed, or ornamented objects such as buttons or the like in order that quantitative and qualitative color comparisons may be reproducibly made. This positioning feature of the invention not only presents the specimen or object to the color measuring instrument in a standard and repeatable manner, but also allows for quantitative and qualitative recording of the position of the specimen or object in the color measuring instrument as well as the color properties of the specimen or object.